A question about naming and such

I currently have a friend that managed to get a name that was on another toon of someone elses. So i take it you can petition a gM to try to get the name from a inactive alt right? Well my biggest question is this. I have two characters atm I'm not leveling and saving those names for Cataclysm, due to the class and races i want to associate the name with. How can I be sure that no GM will somehow give away the name to another player because these two toons are inactive?